Celebrities are migrating to Twitter in astounding numbers. Or so we think.

I've set out to determine if the most-followed celebrities (according to WeFollow) on Twitter are really who they say they are. Is it someone pretending to be a celeb? Is it their publicist taking care of the "trivial" task of updating their Twitter profile? You might be surprised to know that most celebrities are really tweeting. And that's pretty cool.

The top 10

Britney Spears is tweeting sometimes.Photo by Don Reisinger/CNET

1. Britney Spears Britney Spears is a celebrity of the first order. But if you read through her profile, you quickly realize that she's only tweeting a portion of the time. When she's not, other people in her entourage are. Britney signs all her tweets with "~Britney." Seems possible.

Verdict: @BritneySpears is the real Britney Spears.

2. Jimmy Fallon Jimmy Fallon tweets on the @JimmyFallon Twitter account. There's no doubt about it. He talks about things only Jimmy could shed light on. And most importantly, he talks about his tweeting on his show, "Late Night with Jimmy Fallon." No worries here: it's the real guy.

Verdict: @JimmyFallon is really JimmyFallon.

3. Shaquille O'Neal Dubbed @THE_REAL_SHAQ, Shaquille O'Neal's Twitter account is one of the most entertaining in this roundup. Shaq posts pictures of himself, sends brief messages out to followers, and unleashes one-liners that will make you chuckle. I don't think there's any debating that @THE_REAL_SHAQ is the real Shaq.

Verdict: @THE_REAL_SHAQ is really him.

4. Lance Armstrong Lance Armstrong is definitely tweeting on the @LanceArmstrong account. He tweets about his travel around the U.S. He talks about where he's riding today and most importantly, he uploads personal pictures to his TwitPic account.

Verdict: @LanceArmstrong is the real deal.

5. Ellen DeGeneres Ellen DeGeneres is tweeting on her show's Twitter profile, @TheEllenShow. On multiple occasions she has said on her show that she tweets and a recent update provided a TwitPic link to an image of her mother. She also tends to make references to events in her life that others might not know.

Verdict:@TheEllenShow is the real Ellen DeGeneres

6. Perez Hilton @PerezHilton is updated by gossip blogger Perez Hilton. There's no doubt about it. He tweets about blog posts he's writing and discusses celebrities with his followers. Plus, the awkward clip-by-clip image on his profile of him dancing could only come from the source.

Verdict: @PerezHilton is the real gossip blogger.

Seacrest. Out?Photo by Don Reisinger/CNET

7. Ryan Seacrest Though his Twitter profile says it's the official Ryan Seacrest profile, I'm not convinced that he's really tweeting. Many of the tweets in Seacrest's stream come from "Team Seacrest" (whatever that is) and others come from his radio show producers. Ostensibly, those that don't have a signature are Seacrest. But even that is up for debate.

Verdict: @RyanSeacrest is the celebrity's real account, but he might not be tweeting.

8. Demi Moore If you want to read what Demi Moore is up to on Twitter, the only way to find out is to follow @mrskutcher. She updates her stream with information about her life that only she would know. She even posts pictures that prove it's her.

10. Wil Wheaton Best known for his portrayal of Wesley Crusher on "Star Trek: The Next Generation," Wil Wheaton has quickly become a favorite among Twitter users for his love of tech. And that shines through in all his authentic tweets. Whether it's a discussion about Atari or the iPhone, Wil always has something interesting to say.

Verdict: @Wilw is operated by Wil Wheaton.

The real fakes

The most-followed celebrities are really tweeting. But that doesn't mean there aren't some fakes. Here's a quick list of some fake celebrity profiles you'll need to watch out for.

Christopher Walken Christopher Walken's Twitter profile is easily one of the funniest on Twitter. But it's also a fake. At least it's good for a laugh.

George W. Bush The George W. Bush Twitter account is rife with veiled insults of our former president and some "misquotes" that he doesn't like. Yeah, it's a fake.

Megan Fox Dubbed @The_Megan_Fox, the fake Megan Fox Twitter account is, at times, sexual in nature. But when the person updating the profile is done discussing her body, it can be quite funny.

Stephen Colbert There are dozens of fake Stephen Colbert profiles on Twitter. But the @StephenColbert account is the most popular and, arguably, the best of the bunch. The user cracks quite a few jokes, sounds like Colbert, and unleashes some one-liners that would make Ronald Reagan proud. If you want to follow the real Stephen Colbert, click here.

Tina Fey Tina Fey's Twitter profile is about as fake as they come. The person impersonating her makes off-hand remarks about Tina and her life, but most of the updates are strange discussions on candy and food.